CN108215516B

CN108215516B - Image forming apparatus, recording medium, and image forming system

Info

Publication number: CN108215516B
Application number: CN201711389168.6A
Authority: CN
Inventors: 芦泽克久; 望月裕史
Original assignee: Canon Finetech Nisca Inc
Current assignee: Canon Finetech Nisca Inc
Priority date: 2016-12-22
Filing date: 2017-12-21
Publication date: 2021-05-11
Anticipated expiration: 2037-12-21
Also published as: US10131157B2; US20180178546A1; CN108215516A

Abstract

The invention discloses an image forming apparatus, a recording medium, and an image forming system. Provided is an image forming apparatus capable of shortening an image forming time and maintaining image quality. The printing device is provided with: a printing section having a thermal head and a film conveyance motor that conveys a transfer film; a memory for storing print data for each color component; and a control section for controlling the printing section. The control unit adjusts an image length when an image is formed on a transfer film by the thermal head based on print data for each color component, based on gradation values of pixels of a pixel group corresponding to 1 line in the main scanning direction of the thermal head constituting the print data for each color component stored in the memory, and an image formation rate indicating a ratio of the number of pixels having a color component to the number of pixels constituting the pixel group corresponding to 1 line.

Description

Image forming apparatus, recording medium, and image forming system

Technical Field

The present invention relates to an image forming apparatus, a recording medium, and an image forming system, and more particularly, to an image forming apparatus that forms an image on a medium using an ink ribbon containing a plurality of colors of ink, a program for causing a computer to function as a part of the image forming apparatus, a computer-readable recording medium containing the program, and an image forming system including an image forming apparatus that forms an image on a medium using an ink ribbon containing a plurality of colors of ink, and a computer that can communicate with the image forming apparatus.

Background

Conventionally, there have been widely known image forming apparatuses for forming an image on a transfer medium such as a transfer film or an image carrier, or a print medium such as a card, a sheet, or a tube. In such an image forming apparatus, for example, the following printing methods are used: an indirect printing method of forming an image (mirror image) on a transfer medium using an ink ribbon and then transferring the image formed on the transfer medium to a printing medium; a direct printing system in which an image is directly formed on a printing medium using an ink ribbon.

In such an image forming apparatus, color printing is generally performed in which images made of a plurality of colors of ink are superimposed to generate a color image. That is, color printing is performed by superimposing an image of a plurality of colors of ink (e.g., YMC ink) on a medium (a transfer medium in the indirect printing method or a print medium in the direct printing method) in accordance with print data (e.g., Y (yellow), M (magenta), and C (cyan)) obtained by converting input print data or input image data.

In color printing, when the printing position of the image of each color ink with respect to the medium is shifted, the color image printed on the medium looks blurred, and therefore the printing quality (image quality) is degraded. This phenomenon of the printing position shift of the image of each color ink is generally referred to as "color shift", and various techniques of correcting the printing position of each color ink image are disclosed.

For example, a technique of printing a density correction pattern and a color shift correction pattern on an intermediate transfer belt to shorten a correction time (see patent document 1), a technique of performing resist adjustment using an unused area not used for image printing in an image formable area (see patent document 2), a technique of nipping a thermal head and a platen with a mark formed on a transfer medium on an upstream side of a sensor and then performing head seeking of the transfer medium and the ink ribbon (see patent document 3), and the like have been proposed.

In addition, the image forming apparatus often constitutes an image forming system together with a computer. A hard disk drive of a computer is provided with an object generation application for generating a desired image object (image data) in accordance with a print medium and a printer driver for creating print data for an image forming apparatus from the image object as necessary, and the image object or the print data generated on the computer side is delivered to the printing apparatus side (see, for example, patent document 4).

Documents of the prior art

Patent document 1: japanese laid-open patent publication No. 2008-3396

Patent document 2: japanese patent laid-open publication No. 2010-204547

Patent document 3: japanese patent No. 5848129

Patent document 4: japanese patent laid-open publication No. 2010-89300

Disclosure of Invention

However, in the field of the image forming apparatus, the image forming process time (printing time) is shortened year by year in accordance with the user's demand. In the background of this shortening of the image forming process time, there is an improvement in the amount of heat generation per unit time in the heating elements constituting the thermal head, for example. However, as a disadvantage, if an image with a wide range and high gradation is formed in the main scanning direction, for example, by heating the heating element with respect to the transfer medium through the ink ribbon, the transfer medium physically stretches due to the heating of the heating element. If an image is formed on the transfer medium with the next ink without taking this elongation into consideration, a color shift is caused. In the case of the indirect printing method, if a transfer medium in which color shift occurs is transferred to a printing medium, the printing quality of an image transferred to the transfer medium is degraded. This phenomenon is not limited to the indirect printing method, and similarly occurs in the direct printing method for a medium having thermal elasticity (for example, a tube, a film, or the like).

In view of the above, an object of the present invention is to provide an image forming apparatus, a program, a recording medium, and an image forming system that can shorten the time for forming an image on a medium and maintain the quality of the image formed on the medium.

In order to solve the above problem, a first aspect of the present invention provides an image forming apparatus for forming an image on a medium using an ink ribbon containing a plurality of colors of ink, the image forming apparatus including: an image forming unit having a thermal head and a medium conveying part for conveying the medium; a holding unit for holding print data of each color component; and a control unit that controls the image forming unit, wherein the control unit adjusts an image length when an image is formed on the medium by the thermal head based on the print data for each color component, based on a gradation value of a pixel group corresponding to 1 line in a main scanning direction of the thermal head constituting the print data for each color component stored in the storage unit, and an image formation rate indicating a ratio of a number of pixels having a color component to a number of pixels constituting the pixel group corresponding to the 1 line.

In the first aspect, the control unit may adjust the image length when forming an image based on print data for each color component by changing the line cycle of the thermal head and/or the conveyance speed of the medium by the medium conveyance section. The control means may detect a tone value and an image formation rate from the print data for each color component, and adjust an image length when forming an image based on the print data for each color component based on the detected tone value and image formation rate. Further, the control means may generate print data for each color component from the input image data and then store the generated print data for each color component in the storage means.

Further, the control unit may adjust the elongation in the sub-scanning direction of the thermal head generated in the medium for every 1 line when forming an image based on the print data of each color component, according to the gradation value and the image forming rate. Further, the control means may adjust the image length when forming an image based on print data for each color component so as to be a predetermined constant value.

In order to solve the above problem, a second aspect of the present invention provides a recording medium having a program recorded thereon, the program causing a computer to function as: a generation unit that generates print data for each color component from the image data; and a detection unit that detects a gradation value of pixels constituting a pixel group corresponding to 1 line in the main scanning direction of the thermal head of the print data for each color component generated by the generation unit, and an image formation rate indicating a ratio of the number of pixels having a color component to the number of pixels constituting the pixel group corresponding to the 1 line. In the second aspect, the computer may also function as a determination unit that determines an adjustment value of an image length to be formed based on print data for each color component when an image is formed on a medium by the thermal head, based on the gradation value and the image formation rate detected by the detection unit.

In order to solve the above-described problems, a third aspect of the present invention provides an image forming system including an image forming apparatus that forms an image on a medium using an ink ribbon containing a plurality of colors of ink, and a computer that can communicate with the image forming apparatus, the image forming system including: a generation unit that generates print data for each color component from the image data; a detection unit that detects a gradation value of a pixel constituting a pixel group corresponding to 1 line in a main scanning direction of the thermal head of the print data for each color component generated by the generation unit, and an image formation rate indicating a ratio of a number of pixels having a color component to a number of pixels constituting the pixel group corresponding to the 1 line; and a determining unit configured to determine an adjustment value of an image length formed based on the print data for each color component when the thermal head forms an image on the medium, based on the gradation value and the image formation rate detected by the detecting unit.

According to the present invention, since the image length when the thermal head forms an image on a medium based on print data of each color component is adjusted according to the gradation value and the image formation rate, color shift can be prevented regardless of the elongation of the medium caused by heating of the thermal head, and the following effects can be obtained: the heat generation amount of the thermal head can be increased to shorten the image forming time and maintain the quality of the image formed on the medium.

Drawings

Fig. 1 is a block diagram showing a configuration of a control/communication system of a printing system according to a first embodiment to which the present invention is applicable.

Fig. 2 is a front view showing a schematic configuration of a printing apparatus constituting a printing system.

Fig. 3 is an explanatory view of an operation posture of a printing unit of the printing apparatus, where (a) shows a state where the printing unit is in a standby posture, (B) shows a state where the printing unit is in a printing posture, and (C) shows a state where the printing unit is in a conveyance posture.

Fig. 4 is a front view of the printing apparatus at the time of transfer.

Fig. 5 is an explanatory view schematically showing an image formation start position of the transfer film, where (a) shows a case where the image formation start position is set using a flag on the upstream side with respect to the image formation direction, and (B) shows a case where the image formation start position is set using a flag on the downstream side with respect to the image formation direction.

Fig. 6 is an explanatory view of a transfer position of the transfer film at the time of transfer, where (a) shows a case where no extension is generated in the print area, and (B) shows a case where extension is generated in the print area.

Fig. 7 is a functional block diagram of a control unit of a host device constituting the printing system.

Fig. 8 is a flowchart of a processing routine of the printer driver executed by the CPU of the control unit of the higher-level apparatus.

Fig. 9 is an explanatory diagram schematically showing an example of a screen displayed on the monitor of the upper apparatus by the target generating section.

Fig. 10 is an explanatory diagram of a case where the control unit of the host apparatus detects the gradation value and the image formation rate of each pixel group of print data corresponding to 1 line in the main scanning direction of the thermal head.

Fig. 11 is a graph schematically showing the relationship between the gradation value and the image formation rate and the elongation coefficient.

Fig. 12 is a flowchart of a card issuance routine executed by a CPU of a microcomputer unit (MCU) of the control unit of the printing apparatus.

Fig. 13 is a flowchart of the printing system according to the second embodiment to which the present invention is applicable, where (a) shows a processing routine of the printer driver executed by the CPU of the control unit of the host device, and (B) shows an adjustment value determination routine executed by the CPU of the MCU of the control unit of the printing device.

Fig. 14 is a flowchart of the printing system according to the third embodiment to which the present invention is applicable, where (a) shows a processing routine of the printer driver executed by the CPU of the control unit of the host device, and (B) shows an adjustment value determination routine executed by the CPU of the MCU of the control unit of the printing device.

(symbol description)

1: a printing device (image forming apparatus); 40: a thermal head; 41: an ink ribbon; 46: a transfer film (medium); 49: a film conveying roller (a part of the medium conveying unit); 70: a control unit (control means); 77: a memory (holding unit); 100: a printing system (image forming system); 152: a target generation unit (generation means); 153: a printer driver (detection unit, determination unit); b: a printing section (image forming unit); mr 5: a film conveyance motor (a part of the medium conveyance section).

Detailed Description

(first embodiment)

Hereinafter, a first embodiment in which the present invention is applied to a printing system including a printing apparatus and a computer will be described with reference to the drawings.

1. Structure of the product

1-1. printing System 100

As shown in fig. 1, the printing system 100 of the present embodiment includes: a printing device 1 for printing and recording characters and images on a card and recording information on the card magnetically or electrically; and a host device 101 (e.g., a host computer such as a personal computer) capable of communicating with the printing system 1.

The printing apparatus 1 is connected to the host apparatus 101, and can instruct a recording operation or the like by transmitting print data, magnetic recording data, electric recording data, or the like from the host apparatus 101 to the printing apparatus 1. The printing apparatus 1 includes an operation panel unit (operation display unit) 5, and can perform a recording operation instruction from the operation panel unit 5 in addition to the recording operation instruction from the host apparatus 101.

1-2. upper device 101

The host device 101 includes a CPU, a ROM, a RAM, a hard disk drive (hereinafter abbreviated as HDD), and a communication unit 155 (see fig. 7) including a communication interface as a hardware configuration.

To the host device 101, an image input device 104 such as a digital camera or a scanner, an input device 103 such as a keyboard or a mouse for inputting commands and data to the host device 101, and a monitor 102 such as a liquid crystal display for displaying data generated by the host device 101 are connected.

1-3. printing apparatus 1

1-3-1. mechanism part

As shown in fig. 2, the printing apparatus 1 includes a housing 2, and includes an information recording portion a, a printing portion B, a rotating member F, and a curl correcting mechanism G in the housing 2. The printing apparatus 1 further includes a medium supply unit C and a medium storage unit D that are attachable to the housing 2, and a reject stacking unit 54 that is attached to a side surface of the housing 2 opposite to the medium storage unit D.

(1) Information recording part A

The information recording section a includes a magnetic recording section 24, a noncontact IC recording section 23, and a contact IC recording section 27. These three recording units are selectively configured, and one or more recording units are attached according to the user's desire.

(2) Media supply part C

The medium supply section C accommodates a plurality of cards Ca in an aligned (inclined) upright posture. A separation opening 7 is formed at the bottom of the front end thereof, and the front-most cards Ca are sequentially drawn out and supplied by a pickup roller 19. In the present embodiment, the card Ca is a card having standard (standard) dimensions of 85.6 mm in width and 53.9 mm in length. The pickup roller 19 is rotated by a driving force of a pickup motor (stepping motor) not shown.

(3) Rotating member F

The blank card Ca drawn out from the medium supply section C is carried into the rotating member F by the carrying-in roller 22 disposed on the inclined medium conveying path P0. The rotating member F includes a rotating frame 50 rotatably shaft-supported to the housing 2 and two roller pairs 20, 21 rotatably shaft-supported to the rotating frame 50. The carry-in roller 22 and the roller pairs 20 and 21 are rotated by a driving force of a first card conveying motor (a stepping motor capable of forward and reverse rotation), not shown, and the turning member F is rotated by a driving force of a turning motor (a stepping motor capable of forward and reverse rotation), not shown. Further, a gear is formed on the outer periphery of the turret 50 and meshes with a gear fitted to a motor shaft of the swing motor.

The magnetic recording portion 24, the noncontact IC recording portion 23, and the contact IC recording portion 27 are disposed on the outer periphery of the rotary member F. The roller pairs 20 and 21 form a medium conveying path 65 for conveying the card Ca to any of the

recording units

23, 24, and 27, and data is magnetically or electrically written to the card Ca by the recording units. Further, a temperature sensor Th such as a thermistor for detecting an ambient temperature (outside air temperature) is disposed in the vicinity of the rotation member F, and temperature correction of a heating element such as a thermal head or a heat roller (described later) provided in the printing portion B is performed based on the ambient temperature detected by the temperature sensor Th.

(4) Printing part B

The printing section B includes: an image forming section B1 for forming an image on the transfer film 46 by superimposing the ink images of the respective colors of the ink ribbon 41 on each other by the thermal head 40; and a transfer section B2 for transferring the image formed on the transfer film 46 to the card Ca conveyed on the horizontal medium conveyance path P1 by the heat roller 33. The printing section B includes a film conveyance mechanism 10 that conveys (the image forming region of) the transfer film 46 across the image forming section B1 and the transfer section B2.

Further, the printing section B is provided with a horizontal medium conveyance path P1 for conveying the card Ca on an extension of the medium conveyance path 65. A pair of conveying

rollers

29 and 30 for conveying the card Ca to the transfer section B2 is disposed on the horizontal medium conveying path P1.

(5) Curling straightening mechanism G

A horizontal medium conveyance path P2 for conveying the transferred card Ca to the storage and accumulation section 60 is provided on the downstream side of the transfer section B2 along the extension of the horizontal medium conveyance path P1. The pair of conveying

rollers

37 and 38 for conveying the card Ca is disposed on the horizontal medium conveying path P2. The rollers (including the platen roller 31) of the conveying roller pair 29 to the conveying roller pair 38 disposed in the horizontal medium conveying paths P1 and P2 are rotated by the driving force of a second card conveying motor (a stepping motor that can rotate forward and backward), not shown.

The conveying

roller pair

37, 38 constitutes a part of the curl correcting mechanism G. The curl correcting mechanism G presses the central portion of the card Ca, which is sandwiched (nip) between the pair of conveying

rollers

37 and 38, with the curl correcting member 34 having a downward convex shape, and thereby sandwiches the card Ca between the concave curl correcting member 35 having a fixed position, thereby correcting the warp generated in the card Ca by the heat transfer of the heat roller 33. The curl correcting mechanism G is configured to be able to advance and retreat the curl correcting member 34 in the vertical direction shown in fig. 2 by a structure including the eccentric cam 36.

(6) Medium storing part D

The medium accommodating portion D has: a storage stacking part 60 having a card placing table for storing the card Ca conveyed from the curl correcting mechanism G side; and an elevating mechanism 61 configured to move downward in fig. 2 in accordance with the number of cards Ca stacked on the card table.

(7) Details of the printing section B

Next, the printing section B will be described in detail in the order of the operation posture (position), the image formation start position, and the transfer start position of the image forming section B1, the transfer section B2, and the printing section B.

(7-1) image Forming section B1

(a) Main components of image forming portion B1

The platen roller 45 and the thermal head 40 are main components constituting the image forming unit B1, and the thermal head 40 is disposed at a position facing the platen roller 45. At the time of image formation, the platen roller 45 is pressed against the thermal head 40 via the transfer film 46 and the ink ribbon 41. That is, the platen roller 45 is configured to be able to advance and retreat with respect to the thermal head 40 by rotating a first eccentric cam, not shown.

The thermal head 40 has a plurality of (1300 in this example) heating elements arranged in a line in the main scanning direction, and the heating elements are selectively controlled by a head control IC (not shown) in accordance with print data to form an image on the transfer film 46 via the ink ribbon 41. In the present embodiment, the film transport mechanism 10 transports the transfer film 46 at a transport speed of 0.8ms (1/1000 seconds) (hereinafter, this transport speed is referred to as a reference transport speed) for every 1 line (line) of the thermal head 40 at the time of image formation, and the line cycle of the thermal head 40 (the image formation time of 1 line) is also set to 0.8[ ms/line ] (hereinafter, this line cycle is referred to as a reference line cycle). The reference transport speed and the reference line period are set on the premise that the transfer film 46 does not stretch during image formation by the thermal head 40.

(b) Transfer film 46

The transfer film 46 is formed in a belt shape having a width slightly larger than the width direction of the card Ca, and is formed by laminating an ink receiving layer for receiving ink of the ink ribbon 41, a protective layer for protecting the surface of the ink receiving layer, a release layer for promoting the integral peeling of the ink receiving layer and the protective layer by heating, and a base material (base film) in this order.

As shown in fig. 5 a, marks for determining an image formation start position, which are formed so as to intersect a width direction (main scanning direction of the thermal head 40) indicated by an arrow (sub-scanning direction of the thermal head 40), are formed at regular intervals on the transfer film 46, and these marks are set to an image formation region Ri therebetween. That is, the image forming region Ri is defined by an upstream flag Ma and a downstream flag Mb in the image forming direction. In the present embodiment, the size of the image forming region Ri in the image forming direction (the lateral direction in fig. 5 a) is set to 94[ mm ], the size in the width direction (the vertical direction in fig. 5 a) is set to 60[ mm ], and the thicknesses (widths) of the flags Ma and Mb are set to 4[ mm ], respectively.

In fig. 5(a), the rectangular area indicated by the solid line in the image forming area Ri is the printing area Rp of the thermal head 40, and the area indicated by the two-dot chain line is the size of the card Ca. In the present embodiment, the printing area Rp of the thermal head 40 is set to 86.6 mm in the lateral direction of fig. 5 a and 54.9 mm in the longitudinal direction, and has a margin (larger than the card Ca) of about 0.5 mm in each of the vertical and horizontal directions with respect to the card Ca of the standard size. In other words, the distance from the front end of the mark Ma to the printing area Rp (image formation end position) of the thermal head 40 and the distance from the rear end of the mark Mb to the image formation start position PA are 3.7[ mm ], respectively.

As shown in fig. 2, the transfer film 46 is wound or drawn around or from the supply roll 47 and the take-up roll 48 in the transfer film cartridge by driving of the motors Mr2 and Mr 4. That is, in the transfer film cartridge, the supply spool 47A is disposed at the center of the supply roller 47, the winding spool 48A is disposed at the center of the winding roller 48, the rotational driving force of the motor Mr2 is transmitted to the supply spool 47A via a gear not shown, and the rotational driving force of the motor Mr4 is transmitted to the winding spool 48A via a gear not shown. As the motors Mr2 and Mr4, DC motors that can rotate in the forward and reverse directions are used. The motor shafts of the motors Mr2 and Mr4 are provided with encoders, not shown, which detect the rotational speeds of the motors, respectively, at positions on the opposite side to the output shaft side.

In the present embodiment, the transfer film 46 before the transfer process is wound around the supply spool 47A, and the used transfer film 46 (the portion after the transfer process in the transfer section B2) is wound around the winding spool 48A. Therefore, when performing the image forming process (also referred to as a primary transfer process) and the transfer process (also referred to as a secondary transfer process) on the transfer film 46, the transfer film 46 is once drawn out from the supply spool 47A toward the take-up spool 48A, and the image forming process and the transfer process are performed while the transfer film 46 is taken up by the supply spool 47A.

(c) Film conveying mechanism 10

The film conveying roller 49 is a main driving roller for conveying the transfer film 46, and the conveying amount and the conveying stop position of the transfer film 46 are determined by controlling the driving of the film conveying roller 49. The film conveying roller 49 is connected to a film conveying motor Mr5 (stepping motor) capable of rotating forward and backward. When the film conveying roller 49 is driven, the motors Mr2 and Mr4 are also driven, but the transfer film 46 drawn out from one of the supply roller 47 and the take-up roller 48 is taken up by the other, and the auxiliary function of film conveyance is performed by a member for applying tension to the transferred transfer film 46. An encoder, not shown, is provided on the roller shaft of the film conveying roller 49.

A pinch roller 32a and a pinch roller 32b are disposed on the circumferential surface of the film conveying roller 49. Further, a tension receiving member 52 is provided to prevent the

pinch rollers

32a and 32b from being separated from the film conveying roller 49 due to the tension of the transfer film 46 generated when the transfer film 46 is pressed against the film conveying roller 49.

The

pinch rollers

32a and 32b are configured to be able to advance and retreat with respect to the film conveying roller 49 by rotating a second eccentric cam, not shown, and the tension receiving member 52 is also configured to be able to advance and retreat with respect to the transfer film 46 by rotating the second cam. The roller shafts of the

pinch rollers

32a and 32b and both end portions of the tension receiving member 52 are supported by support members (not shown) to which rollers that come into contact with the second eccentric cam are fastened. Fig. 2 shows a state in which the

pinch rollers

32a and 32b are pushed toward the film conveying roller 49, the transfer film 46 is wound around the film conveying roller 49, and the tension receiving member 52 is in contact with the transfer film 46. Thereby, the transfer film 46 is accurately conveyed by a distance corresponding to the rotation speed of the film conveying roller 49.

Therefore, the film conveying mechanism 10 has the following functions: by driving the film conveying roller 49 disposed between the image forming section B1 and the transfer section B2, the transfer film 46 is conveyed forward and backward among the supply roller 47, the image forming section B1, the transfer section B2, and the take-up roller 48, and the image forming region Ri of the transfer film 46 is positioned at an appropriate position in the image forming section B1 and the transfer section B2.

Further, a sensor Se1 is disposed between the take-up roller 48 and the image forming section B1 (thermal head 40, platen roller 45), and the sensor Se1 has a light emitting element and a light receiving element and detects a mark formed on the transfer film 46. In addition, a cooling fan 39 for cooling the thermal head 40 is disposed in the vicinity of the thermal head 40.

(d) Ink ribbon 41

The ink ribbon 41 is stored in the ink ribbon cassette 42, and is stored in the ink ribbon cassette 42 in a state of being stretched between a supply roller 43 that supplies the ink ribbon 41 and a winding roller 44 that winds the ink ribbon 41. A winding spool 44A is disposed at the center of the winding roller 44, a supply spool 43A is disposed at the center of the supply roller 43, the winding spool 44A is rotated by the driving force of the motor Mr1, and the supply spool 43A is rotated by the driving force of the motor Mr 3. As the motors Mr1 and Mr3, DC motors that can rotate in the forward and reverse directions are used. The motor shafts of the motors Mr1 and Mr3 are provided with encoders, not shown, which detect the rotational speeds of the motors, respectively, at positions on the opposite side to the output shaft side.

The ink ribbon 41 is configured by repeating a color ink panel of Y (yellow), M (magenta), and C (cyan) and a Bk (black) ink panel in a planar order in the longitudinal direction. In the present embodiment, sublimation ink is used for the color ink panel of Y, M, C, and melting ink is used for the Bk ink panel.

Between the supply roller 43 and the image forming section B1 (thermal head 40, platen roller 45), a sensor Se2 is disposed, and the sensor Se2 detects the position of the ink ribbon 41 by light from the light emitting element side being blocked by the Bk ink panel on the light receiving element side, and performs head seeking of the ink ribbon 41 to the image forming section B1.

(e) Relation with transfer part B2

The ink ribbon 41, on which the image formation on the transfer film 46 is completed, is peeled from the transfer film 46 by the peeling roller 25 and the peeling member 28. The peeling member 28 is fixed to the ink ribbon cassette 42, and the peeling roller 25 is brought into contact with the peeling member 28 at the time of image formation to sandwich the transfer film 46 and the ink ribbon 41 therebetween, thereby performing peeling. Then, the peeled ink ribbon 41 is wound around the winding roller 44 by the driving force of the motor Mr1, and the transfer film 46 is conveyed to the transfer section B2 by the film conveying mechanism 10. Further, the roller shaft of the platen roller 45 and both end portions of the peeling roller 25 are supported by support members (not shown) to which rollers that come into contact with the first eccentric cam are fastened, and the first cam rotates to release the pressure contact of the platen roller 45 with the thermal head 40 and release the contact of the peeling roller 25 with the peeling member 28.

A sensor Se3 for detecting a mark formed on the transfer film 46 is disposed downstream of the film conveying roller 49. When this flag detection is triggered, conveyance of the card Ca that is being held between the pair of

conveyance rollers

29 and 30 on the horizontal medium conveyance path P1 and is stopped (on standby) is started toward the transfer section B2, and the image forming region Ri (print region Rp) of the transfer film 46 and the card Ca reach the transfer section B2 at the same time. As the sensor Se3, a transmission-integrated sensor is used.

(7-2) transfer section B2

In the transfer section B2, the transfer film 46 is nipped by the heat roller 33 and the platen roller 31 together with the card Ca, and the image formed in the image forming region Ri of the transfer film 46 is transferred to the card Ca. That is, at the time of transfer, the heat roller 33 is pressed against the platen roller 31 via (the image forming region Ri of) the card Ca and the transfer film 46, and the card Ca and the transfer film 46 are conveyed in the same direction at the same speed. The heat roller 33 is attached to an elevating mechanism (not shown) so as to press against and separate from the platen roller 31 via the transfer film 46.

The transfer film 46 after the image transfer is separated (peeled) from the card Ca by a peeling pin 79 disposed between the heat roller 33 and a driven roller (a lower roller in fig. 2) constituting the conveying roller pair 37, and is conveyed to the supply roller 47 side. On the other hand, the card Ca to which the image has been transferred is conveyed to the curl correction mechanism G on the downstream side on the horizontal medium conveyance path P2 (see also fig. 4).

(7-3) operating posture of printing section B

The printing section B takes any one of a standby posture, a printing posture, and a conveyance posture by controlling the rotation of the first and second eccentric cams.

(a) Standby posture

Fig. 3(a) is a diagram showing a state in which the printing portion B is in a standby posture. In this state, the

pinch rollers

32a and 32b are not pressed against the film conveying roller 49, and the tension receiving member 52 is not in contact with the film conveying roller 49. The platen roller 45 is not pressed against the thermal head 40, and the peeling roller 25 is not in contact with the peeling member 28.

(b) Printing posture

Fig. 3(B) is a diagram showing a state in which the printing portion B shifts to the printing posture. At this time, first, the

pinch rollers

32a and 32b wind the transfer film 46 around the film conveying roller 49, and the tension receiving member 52 comes into contact with the transfer film 46, and then, the platen roller 45 is pressed against the thermal head 40. In this printing position, the platen roller 45 moves toward the thermal head 40 to sandwich the transfer film 46 and the ink ribbon 41.

In this state, the transfer film 46 is conveyed by the rotation of the film conveying roller 49, and the ink ribbon 41 is wound by the winding roller 44 by the operation of the motor Mr1 and conveyed in the same direction. During this conveyance, when the mark formed on the transfer film 46 passes through the sensor Se1 and the transfer film 46 reaches an image formation start position (described later), an image is formed by the thermal head 40 in the image formation region Ri of the transfer film 46.

The conveyance amount of the transfer film 46 (the distance in the conveyance direction of the transfer film 46) is detected by an encoder provided to the film conveyance roller 49, and the winding of the winding roller 44 by the operation of the motor Mr1 is stopped in accordance with the stop of the rotation of the film conveyance roller 49. Thereby, the image formation in the image formation region Ri of the transfer film 46 is completed by the ink of the first ink panel (for example, Y).

(c) Conveyance posture

After the image formation by the first ink of the ink panel is completed, the printing unit B shifts to the conveyance posture, and the platen roller 45 retracts from the thermal head 40 (the contact of the peeling roller 25 with the peeling member 28 is also released). Fig. 3(C) is a diagram showing a state in which the printing section B is shifted to the conveyance posture. In this state, the

pinch rollers

32a and 32b wind the transfer film 46 around the film conveying roller 49, and the tension receiving member 52 is in contact with the transfer film 46.

In this state, the transfer film 46 is reversely conveyed to the home position (seek position) by the reverse rotation of the film conveying roller 49. At this time, the amount of movement of the transfer film 46 is also controlled by the rotation of the film conveying roller 49, but a predetermined length equal to or longer than the length in the conveying direction of the image forming region Ri in which an image is formed by one color ink panel (for example, Y) is reversely conveyed and returned to the initial position so that the mark exceeds the detection position of the sensor Se 1. Further, the ink ribbon 41 is also rewound by a predetermined amount by the motor Mr3, and then an ink panel of ink for forming an image is made to stand by at an initial position (seek position).

(d) Gesture transfer in printing action

In the color printing operation, after the transfer film 46 and the ink ribbon 41 are conveyed to the initial positions respectively by the conveyance postures, the printing posture shown in fig. 3(B) is again shifted, the platen roller 45 is brought into pressure contact with the thermal head 40, the film conveyance roller 49 conveys the image forming region Ri of the transfer film 46, and the thermal head 40 forms an image with ink of the next ink panel (for example, M).

In this way, the operations of the printing posture and the conveying posture are repeated until the image formation by all or a predetermined ink panel is completed. After the image formation by the thermal head 40 is completed, the pressure contact of the platen roller 45 with the thermal head 40 is released. Then, the film transport motor Mr5 (and the motors Mr2 and Mr4) drives the transfer section B2 to transport the image formation region Ri of the transfer film 46.

(7-4) image formation starting position and transfer starting position

(a) Image formation start position

By driving the film carrying motor Mr5, after the sensor Se1 detects the leading end of the mark Ma, when the mark Ma is carried toward the image forming unit B1 by a predetermined distance (for example, several mm), the formation of an image on the image forming region Ri by the thermal head 40 is started. This position is the image formation start position PA (position 90.3[ mm ] from the front end of the mark Ma) shown in fig. 5 (a). The motor Mr1 is also driven simultaneously, and the transfer film 46 and the ink ribbon 41 are conveyed in the same direction at the same speed in the image forming section B1.

Further, before the image forming process (image formation start), the heating elements constituting the thermal head 40 are preliminarily heated (the heating elements are heated to a predetermined temperature lower than the temperature at which the ink of the ink ribbon 41 is transferred to the image forming area Ri of the transfer film 46).

(b) Transfer start position

Fig. 4 shows a front view of the printing apparatus 1 at the time of transfer in the transfer section B2. In the transfer process, the sensor Se3 detects the mark Mb and performs head seeking. In the present embodiment, a position where the film conveyance motor Mr5 is driven and the transfer film 46 is further conveyed by 30[ mm ] after the sensor Se3 detects the leading end of the marker Mb is set as the transfer start position.

Fig. 6(a) is a diagram schematically showing alignment of the image forming area Ri and the card Ca when no extension occurs in the image forming area Ri of the transfer film 46. As shown in fig. 6(a), in the transfer section B2, the head of the transfer film 46 is sought so that the center Cn of the length of the print region Rp of the thermal head 40 in the image forming direction and the center of the card Ca in the longitudinal direction are at the same position. In this state (a state in which no extension occurs in the image forming region Ri), the transfer film 46 is further conveyed by 30[ mm ] after the sensor Se3 detects the tip of the marker Mb as described above, and the center Cn of the length of the print region Rp in the image forming direction and the center of the card Ca in the longitudinal direction coincide with each other.

1-3-2. control part

As shown in fig. 1, the printing apparatus 1 includes a control unit 70 that controls the operation of the entire printing apparatus 1. The control unit 70 includes a microcomputer 72 (hereinafter abbreviated as MCU72) that controls the printing apparatus 1. The MCU72 includes a CPU that operates as a central processing unit at a high speed, a ROM that stores programs and program data of the printing apparatus 1, a RAM that functions as a work area of the CPU, and an internal bus that connects these.

An external bus is connected to the MCU 72. To the external bus, a communication unit 71 having a communication IC and communicating with the host apparatus 101, and a memory 77 temporarily storing print data on which an image is to be formed on the card Ca, a magnetic stripe to be magnetically or electrically recorded on the card Ca, record data for storing the IC, and the like are connected.

Further, to the external bus, a signal processing unit 73 that processes signals from the sensors and the encoder, an actuator control unit 74 including a motor driver and the like that supplies a drive pulse and drive power to the motors, a thermal head control unit 75 that has the head control IC and controls the thermal energy of the heating elements constituting the thermal head 40, an operation display control unit 76 that controls the operation panel unit 5, a conveyance error due to double conveyance of the information recording unit a and the card Ca, a buzzer operation circuit 78 that operates the buzzer 6 when recording fails due to the information recording unit a, and the like are connected.

2. Background of the invention for printing System 100

Here, the technical background of the printing system 100 according to the present embodiment will be briefly described.

As described in the section of "summary of the invention", the image forming region Ri of the transfer film 46 is elongated in the sub-scanning direction of the thermal head 40 as a result of forming an image on the printing region Rp by the heating elements of the thermal head 40 based on the print data (when the print data includes a large number of high-gradation pixels).

In the printing system 100 of the present embodiment, on the premise that such an extension occurs in the transfer film 46, when the thermal head 40 for print data according to each color component forms an image in the image forming region Ri, the image length of the printing region Rp is adjusted in anticipation of the extension occurring in the transfer film 46. That is, the color shift is prevented by adjusting the image length in the image forming direction of the print area Rp so as to be constant (86.6 mm as described with reference to fig. 5 a in this example).

The present inventors have conducted a large number of experiments using a real machine as to what element of print data causes elongation of the transfer film 46. As a result, it was found that the gradation value of the pixels constituting the pixel group of the print data corresponding to 1 line in the main scanning direction of the thermal head 40 and the image formation rate indicating the ratio of the number of pixels having a color component (of the print data) to the number of pixels constituting the pixel group corresponding to 1 line in the main scanning direction of the thermal head 40 are factors of the elongation of the transfer film 46.

From this finding, in the printing apparatus 1, the image length of the printing area Rp is adjusted so as to be constant when the thermal head 40 forms an image, based on the tone value and the image formation rate for each 1 line. In order to adjust the image length to be constant, the line period may be shortened with respect to the reference line period of the thermal head 40 in anticipation of the extension occurring in the print area Rp. Further, the line period may be changed for every 1 line, but the conveyance speed of the transfer film 46 is maintained at a constant speed when an image is formed in the image forming region Ri.

3. Movement of

Next, the operation of the printing system 100 according to the present embodiment will be described.

3-1. summary of actions

In the printing system 100 of the present embodiment, the upper device 101 converts image data into print data for each color component, and detects a tone value and an image formation rate for each 1 line of the print data for each color component. Next, an adjustment value of the line cycle per 1 line of the thermal head 40 when forming an image in the image forming region Ri (print region Rp) of the transfer film 46 in the printing apparatus 1 is determined based on the gradation value per 1 line and the image forming ratio. The host device 101 transmits print data for each color component and an adjustment value for a line period to the printing device 1. On the other hand, in the printing apparatus 1, an image is formed by the thermal head 40 in the image forming region Ri in accordance with the received print data and adjustment value. These operations are described in detail below.

3-2. actions of the host apparatus 101

As shown in fig. 7, the CPU, ROM, RAM, and HDD of the higher-level device 101 function as a control unit 150. That is, the control unit 150 causes the CPU to function as a main body in accordance with a program (and program data) stored in the ROM and developed in the RAM.

The HDD of the control unit 150 is equipped with a target generation application for generating desired image data (image target) to be printed on the card Ca, a printer driver (application) for generating print data for the printing apparatus 1 from the image data generated by the target generation application, and the like.

The program of the application software may be installed in the HDD via a recording medium readable by the higher-level device 101 such as a CD-ROM, a Flexible Disk (FD), a USB memory, a ZIP, or an MO, or may be acquired from another computer via the communication unit 155 and installed in the HDD when the higher-level device 101 constitutes one member of the network.

The CPU constituting the control section 150 realizes the functions of the object generating section 152 and the printer driver 153 by developing object generating application software and the printer driver installed in the HDD as the application 151 in the RAM simultaneously or selectively. The HDD also functions as a data storage unit 154 that stores data that is being created (processed) or created (processed) in the target creation unit 152 and the printer driver 153.

3-2-1. target generation section 152

The target generation unit 152 includes an individual target generation unit that generates each print target, a target merging unit that merges a plurality of targets, an image data generation unit that generates image data from the merged targets, and a GDI (Graphics Device Interface) that outputs the image data and the like to the printer driver 153, and is referred to in japanese patent application laid-open No. 2004-194041. Each of these units other than the GDI has a GUI (graphical User Interface) function for performing input/output control with the monitor 102, the input device 103, and the image input device 104 by using a function provided from an OS (Operating System).

(1) Individual object generating section

Fig. 9 is a diagram schematically showing an example of a screen displayed on the monitor 102 when a print target of the name "known charm" of the owner printed on the card Ca is created. This example is an example in which the operator inputs "know charm" (text data) from the keyboard of the input device 103 in the "text input" field, inputs print information such as a font name, a font size, a style/decoration, a character color, and a background color with a mouse (not shown) of the input device 103, and displays a print target generated from the input text data and the print information in the preview field.

The operator operates (corrects) the input device 103 while referring to the preview, thereby creating a desired print target (text data), and clicks the OK button. Thus, the individual target generation unit takes in one print target (including the size information of the target), gives a name and a number for specifying the print target, and stores the print target in a predetermined folder. In this example, the print target displayed in the "preview" field is shown as being composed of a plurality of characters, and the same print target such as the font and font size of these characters, but the print target may be composed of one character or may be composed of a plurality of characters, and the characters may have different fonts and font sizes.

The card Ca is generally configured to include various print targets (text data) such as a company name and an ID number to which the owner belongs in addition to the name of the owner, and therefore the individual target generating unit can generate another print target (other than the name) in accordance with the above example and store the generated plurality of print targets in the folder. Since company names are common, a print target stored in another folder may be copied and stored in the folder.

In addition, in the card Ca, image objects such as a photograph of the face of the owner, a LOGO of a company, and a background image of the card are often printed, and these image objects may be stored in the folder or other folders. Such an image object may be taken in from the image input device 104, or an image object stored in another computer may be used via the communication unit 155.

(2) Target merging section

The operator creates a desired image object to be printed on the card Ca based on the plurality of objects stored in the folder. The object merging unit displays the entire preview image on the monitor 102, and assists the arrangement of the plurality of objects by the operator. Thus, the operator can obtain a merge destination in which the owner's name, company name, ID number, face photograph, LOGO, and the like are arranged at a desired position.

The object merging unit determines whether or not the OK button of the preview image is clicked, and if clicked, determines that the arrangement of the image (merging) objects to be printed on the card Ca is fixed, and acquires the position information of each object constituting the merging object. Therefore, the object merging unit has a function of adding position information of each object. In the present embodiment, the position information of each object is stored in the folder, but may be stored in another folder.

(3) Image data generating unit

The image data generating unit converts each print target of the text data into image data such as a bitmap, and generates image data in which all the image data are combined into one for each surface of the card Ca.

The image data generating unit allows the operator to select which of the double-sided printing and the single-sided printing the generated image data is to be used for, and which of the front surface and the back surface of the card Ca is to be used for, and obtains the result as attribute information of the image data. Further, the image data generating unit requests the operator to input data to be recorded in the magnetic stripe or IC of the card Ca and to specify the recording unit (23, 24, 27), and obtains the input result as recording data.

Then, the image data generation unit outputs the image data, the attribute information, and the recording data to the GDI by using an API (Application Program Interface) function.

(4)GDI

The GDI submits the image data, the attribute information, and the recording data stored in one folder to the printer Driver 153 by means of a DDI (Device Driver Interface) function, refer to japanese patent application laid-open No. 2002-91428.

3-2-2 printer driver 153

The printer driver 153 includes a conversion processing section that converts image data into print data for each color component, a detection processing section that detects a gradation value and an image formation rate of the print data for each color component, a determination processing section that determines an adjustment value of a line period for each 1 line of the thermal head 40, and a transmission processing section that transmits a folder containing the print data, attribute information, recording data, and the like to the printing apparatus 1.

Fig. 8 is a flowchart of a processing routine of the printer driver executed by the CPU of the control section 150. The conversion processing section executes the conversion processing of step (hereinafter, simply referred to as "S") 202, the detection processing section executes the gradation value and image formation rate detection processing of S204, the determination processing section executes the adjustment value determination processing of S206, and the transmission processing section executes the transmission processing of S208, each mainly including a CPU. The processing performed by each unit is described below.

(1) Conversion processing unit

The conversion processing unit roughly executes two conversion processes on the image data among the data in the folder received from the object generating unit 152 (GDI).

The first conversion process is a mirror conversion process of converting image data into a mirror image. The mirror image conversion process is not necessarily performed on the higher-level device 101 side (conversion processing unit), and may be performed on the printing device 1 side for print data of each color component.

The second conversion process is the following three image conversion processes for the image data after the mirror image conversion. In the present embodiment, in the image conversion processing, each pixel constituting Y, M, C, Bk print data is converted by 256 gradations having gradation values in the range of 0 to 255.

1) Conversion from image data having R (red), G (green), and B (blue) as image components to print data having Y, M, C as color components.

2) The transformation (correction) arbitrarily performed at the time of the transformation of 1) above is, for example, as follows:

(a) gamma conversion (adjustment of color tone to user preference, details of which are described in, for example, japanese patent laid-open No. h 8-80640).

(b) The linear conversion (correction of color characteristics (output to the thermal head 40 — print density)) of the printing apparatus 1 is described in detail, for example, in japanese patent application laid-open No. 6-30271.

(c) Environmental correction (correction of color characteristics due to the environment such as the temperature in the thermal head and the printing apparatus 1, for example, see Japanese patent laid-open No. 63-115766).

(d) Edge emphasis conversion (conversion for emphasizing, for example, the outline of a face, and the like, and the details thereof refer to japanese patent application laid-open No. 2007-320050).

(e) The head resistance correction (correction of the color development characteristics of the structure of the thermal head 40, for example, see japanese patent laid-open No. 7-125284).

When the above-described conversion (correction) from (c) to (e) is performed, predetermined information (such as an ambient temperature) of the printing apparatus 1 is acquired in advance via the communication unit 155.

3) A dither transform for image data having Bk (black) as a color component. This dither conversion is performed in the case where the ink of the Bk ink panel of the ink ribbon 41 is the melting ink as shown in this example, but the dither conversion is also performed for the color ink panel in the case where the color ink panel of the ink ribbon 41 is the melting type (the case other than this example).

(2) Detection processing unit

Fig. 10 schematically shows a pixel of print data of one color (for example, Y) corresponding to the print area Rp of the thermal head 40 shown in fig. 5. In the print data of the present embodiment, the number of pixels in the main scanning direction is 1300 in accordance with the number of heating elements in the main scanning direction of the thermal head 40, and the number of pixels in the sub-scanning direction is 2048.

The detection processing unit detects the gradation value and the image formation rate of each pixel group corresponding to 1 line in the main scanning direction of the thermal head 40, as shown in fig. 10, for each piece of print data of Y, M, C converted by the conversion processing unit. In the present embodiment, the number of pixels capable of forming an image for each pixel group of print data corresponding to 1 line in the main scanning direction of the thermal head 40 is 1300, and therefore the image formation rate is a ratio of the number of pixels having a gradation value of 1 or more with respect to the number of pixels of the pixel group of print data corresponding to 1 line of 1300.

(3) Determination processing unit

The determination processing unit determines an adjustment value of a line period per 1 line of the thermal head 40 based on the gradation value and the image formation rate of each pixel group corresponding to 1 line detected by the detection processing unit.

First, the determination processing unit calculates, for each line of Y, M, C print data, the elongation coefficient of each line by image formation using Y, M, C ink for each 1 line, with reference to table 1 below (ratio assignment calculation) based on the gradation value and image formation rate of each pixel group corresponding to 1 line. Even if the gray scale value is an average gray scale value of the pixels constituting the pixel group corresponding to 1 line, the influence on the elongation is greater when the gray scale value is high than when the gray scale value is low, and therefore, a large weighting can be performed by a high gray scale value. In the present embodiment, when the elongation coefficients of all the rows (2048 rows) are all 1.0, the image forming region Ri is elongated by 1.0[ mm ]. That is, when the elongation coefficient of 1 line is 1.0, the elongation of the line is estimated to be 1/2048, that is, about 0.0004883[ mm ].

[ TABLE 1 ]

Fig. 11 is a graph schematically showing the elongation coefficient expressed as the value of the Z axis when the gradation value is set as the X axis and the image forming rate is set as the Y axis. For example, as shown as the fourth region in the figure, when the gray scale value is high (for example, 255 grays) and the image forming rate is large (for example, 100%) in the pixel group of 1 line, the elongation amount of the film 46 increases, and accordingly the elongation coefficient also increases (for example, the elongation coefficient becomes 1). On the contrary, as shown as the first region in the figure, when the tone value is low (for example, 63 tones or less) and the image forming rate is also small (for example, 25% or less), the elongation amount of the film 46 becomes small, and the elongation coefficient becomes small (for example, the elongation coefficient becomes 0.06).

Next, the determination processing unit refers to a predetermined relationship (relational expression or table) between the calculated elongation coefficient and the elongation [ mm ] (estimated value) generated in the image forming region Ri during image formation in the print region Rp of 1 line, and calculates (estimated value of) the elongation of each of the Y, M, C generated in the image forming region Ri during image formation in the image forming region Rp of 1 line.

Since the extension of each of the Y, M, C varies depending on the sublimation degree of each ink panel of the ink ribbon 41 and the absorption degree of the ink receiving layer of the transfer film 46, the above-described relational expression or table can be created by acquiring the value of the extension measured in the printing apparatus 1 in an environment of a reference temperature (e.g., room temperature) in, for example, a thermostatic bath. In this case, for example, the elongation can be measured by printing the print data of 1 line for 1000 lines, and the accuracy of the measured value can be improved by setting the value of 1/1000 as the elongation of 1 line.

Next, the determination processing unit performs temperature correction of the elongation at Y, M, C calculated for each 1 line based on the temperature detected by the temperature sensor Th. Such temperature correction is also performed by referring to a predetermined relational expression or table of the value of the elongation and the temperature value. Such a temperature correction formula or table can be created by obtaining values of the elongation measured in the thermostat for the printing apparatus 1 at intervals of 10 degrees celsius in an environment including, for example, a reference temperature (e.g., room temperature). The temperature correction is performed after the ambient temperature of the printing apparatus 1 is acquired via the communication unit 155. The determination processing unit does not necessarily perform such temperature correction, and may correct the temperature to the reference temperature. In this case, the printing apparatus 1 may perform temperature correction for the adjustment value described below.

Next, the determination processing unit determines the adjustment value of the line period of the thermal head 40 for each line of the print data of each color component in anticipation of the extension occurring in the print area Rp, in accordance with the predetermined relationship between the extension of the print area Rp for each 1 line and the adjustment value of the line period. For example, if the elongation coefficient of 1 line is 1.0, the line will be elongated 0.0004883[ mm ] if it is printed as it is, so the length of 1 line needs to be adjusted from 0.0427734[ mm ] (86.6/2048+0.0004883[ mm ]) to 0.0422851[ mm ] (86.6/2048[ mm ]). In other words, the adjustment is performed so as to shorten the line period in order to set the elongation to 0. In this case, the column period is determined to be negative 1.15478% (adjustment value: -1.15478%) to shorten the column period. In accordance with this determination, in the printing apparatus 1, the line period is adjusted (corrected) to 0.8[ ms/line ] × 0.9884511 of 0.79076[ ms/line ] with respect to 0.8[ ms/line ] of the reference line period of the thermal head 40.

In the above, the determination process of the adjustment value of the line period by the determination processing unit has been described for each stage, but actually, the determination processing unit directly calculates the adjustment value of the line period for each 1 line by substituting the gradation value and the image formation rate for each 1 line detected by the detection processing unit into the equation.

The determination processing unit determines the adjustment value of the line period of the thermal head 40 corresponding to the estimated extension amount of the printing area Rp for each 1 line, and in parallel therewith, determines the adjustment value of the image formation start position PA by the M ink based on the estimated extension amount of the image formation area Ri generated when printing all the lines with the Y ink. Further, an adjustment value of the image formation start position PA by the C ink is determined based on the estimated extension amount of the image formation area Ri generated when printing all lines with the Y ink and the M ink. That is, the image formation start position PA of the predetermined color is changed based on the estimated extension amount of the image formation region Ri due to printing of the preceding color. Further, the estimated elongation at the time of printing of all the lines can be calculated from the sum of the estimated elongations obtained from the elongation coefficients of the 1 line. As described above, when the elongation coefficients of all the rows are all 1.0, the estimated elongation of all the rows is 1.0[ mm ].

The determination processing unit determines an adjustment value of the image formation start position PA as follows. For easy understanding, the following will be described as an example: the estimated amount of extension generated in the image forming region Ri when an image (all lines) is formed on the printing region Rp with the Y ink is 1.0[ mm ], the estimated amount of extension generated in the image forming region Ri when an image is formed on the printing region Rp with the M ink is 0.5[ mm ], and no extension (estimated amount of extension: 0[ mm ]) is generated in the image forming region Ri when an image is formed on the printing region Rp with the C ink.

The image formation start position PA when forming an image with Y ink is 90.3mm from the front end of the flag Ma as described with reference to fig. 5(a) because the unused image formation area Ri is used. The image formation start position PA at the time of forming an image with the M ink is a position (corrected to the 1.0[ mm ] mark Mb side) at which 90.3[ mm ] +1.0[ mm ] - < 91.3[ mm ] from the leading end of the mark Ma because an elongation of 1.0[ mm ] occurs in the image formation region Ri at the time of forming an image with the Y ink in the print region Rp.

The image formation start position PA at the time of forming an image with C ink is a position (corrected to the 1.5[ mm ] mark Mb side) at which 90.3[ mm ] +1.0[ mm ] +0.5[ mm ] + 91.8[ mm ] is located from the tip of the mark Ma because of the respective elongations of 1.0[ mm ] and 0.5[ mm ] in the image formation region Ri at the time of forming an image with Y ink and M ink in the print region Rp. The image formation start position PA at the time of forming an image with Bk ink is a position (corrected to the 1.5[ mm ] mark Mb side) that is 90.3[ mm ] +1.0[ mm ] +0.5[ mm ] +0[ mm ] equal to 91.8[ mm ] from the tip of the mark Ma, as in the case of C ink, because it is estimated that no extension occurs in the image formation region Ri at the time of forming an image with C ink in the print region Rp. That is, the image formation start position PA is corrected to the flag Mb side according to the estimated extension amount of the image formation area Ri.

Further, the above-described determination processing section shows a mode in which the adjustment value for adjusting the line period of the thermal head 40 is determined so that the image length of the print region Rp becomes a constant value (86.6 mm), but the adjustment value for adjusting the transport speed of the transfer film 46 (adjustment value of the transport speed of the transfer film 46 per 1 line) may be determined without changing the line period.

For example, when the elongation coefficient of the target line is 1.0[ mm ], the line cycle is not changed, the transport speed is delayed by 1.15478% (adjustment value: -1.15478%) from the reference transport speed, and the transport speed of the transfer film 46 is set to 0.79076[ ms ] from 0.8[ ms ], so that the print area Rp can be maintained at 86.6[ mm ] in appearance even if the image formation area Ri of the transfer film 46 is elongated.

Thus, when an image is formed by the thermal head 40 for every 1 line in the print area Rp, it can be seen that the elongation in the sub-scanning direction of the thermal head 40, which is generated in the print area Rp, does not occur in appearance.

Then, the determination processing section stores the attribute information and the record data received from the target generating section 152, the Y, M, C, Bk print data converted by the conversion processing section, and the adjusted value of the line period (adjusted value of the transport speed in the folder when the film transport speed is adjusted) per 1 line of the Y, M, C print data and the adjusted value of the image formation start position PA of each color in one folder.

(4) Transmission processing unit

The transmission processing unit transmits the folder created by the determination processing unit in accordance with the instruction of the operator to the printing apparatus 1. At this time, the folder created in accordance with the instruction of the operator may be stored in the data storage unit 154.

3-3 actions of the printing apparatus 1

Next, the card issuing operation on the printing apparatus 1 side will be described mainly by a CPU (hereinafter, simply referred to as CPU) of the MCU72 with reference to a flowchart. For the sake of simplicity, the description is made such that the components constituting the printing apparatus 1 are positioned at the original (initial) positions (for example, the state shown in fig. 2), the initial setting process of developing the program and the program data stored in the ROM in the RAM is completed, and the folder is received from the host apparatus 101 (communication processing unit). Since the operation of the printing section B (the image forming section B1, the transfer section B2) has been described, the description is simplified to avoid redundancy.

As shown in fig. 12, in the card issuance routine, in S302, the image forming section B1 performs a primary transfer process (image forming process) for forming an image on one surface (for example, the front surface) side on the transfer film 46. That is, the thermal head 40 of the image forming section B1 is controlled based on the Y, M, C print data and Bk print data stored in the memory 77, and an image is formed by superimposing Y, M, C of the ink ribbon 41 and Bk ink in the image forming region Ri of the transfer film 46.

At this time, the CPU refers to the print data in the folder and the adjustment value of the line period (in the case of adjusting the film conveyance speed, the adjustment value of the conveyance speed in the folder) and the adjustment value of the image formation start position PA stored in the memory 77, and outputs the print data and the adjustment value of the line period for every 1 line from the adjusted image formation start position to the thermal head control unit 105 (head control IC), thereby selectively heating the heating elements arranged in the main scanning direction and driving the thermal head 40.

In parallel with the primary transfer process in S302, in S304, the CPU extracts the card Ca from the medium supply unit C, performs a recording process for the card Ca using one or more of the magnetic recording unit 24, the noncontact IC recording unit 23, and the contact IC recording unit 27 constituting the information recording unit a based on the recording data in the folder stored in the memory 77, and then conveys the card Ca to the transfer unit B2.

In next S306, in the transfer section B2, a secondary transfer process is performed in which the image formed on the transfer surface of the transfer film 46 is transferred to one surface of the card Ca. Further, the CPU controls so that the temperature of the heater constituting the heat roller 33 reaches a predetermined temperature before the secondary transfer process, and controls so that the card Ca and the image formed on the transfer surface of the transfer film 46 reach the transfer section B2 in synchronization.

In next S308, a curl correction process is performed in which the warp generated by the card Ca is corrected by rotating the eccentric cam 36 and pressing the curl correction member 34 toward the curl correction member 35 and clamping the card Ca with the

curl correction members

34, 35.

Next, in S310, it is determined whether or not the print is double-sided printing based on the attribute information in the folder stored in the memory 77, and in the case of a negative determination, the process proceeds to S320, and in the case of an affirmative determination, in S312, a primary transfer process of forming an image on the other surface (for example, the back surface) side in the next image forming region Ri of the transfer film 46 is performed by the image forming section B1 in the same manner as in S302, and the process proceeds to S316.

In parallel with the primary transfer process in S312, the CPU conveys the card Ca, which is nipped between the pair of conveying

rollers

37 and 38 and positioned to the curl correction mechanism 12, to the rotating member F via the horizontal medium conveying paths P2 and P1 in S314, and rotates the card Ca, which is nipped between the pair of

rollers

20 and 21 at both ends, by 180 ° (reverses the front and back). In the next S316, similarly to S306, a secondary transfer process is performed in which the image formed on the next image forming region Ri of the transfer film 46 is transferred to the other surface of the card Ca in the transfer section B2.

Next, in S318, the curl correction processing for correcting the warp generated by the card Ca by gripping the card Ca with the

curl correction members

34, 35 is performed in the same manner as in S308. Then, in the next step S320, the card Ca is discharged to the housing and stacking unit 60, and the card issuance routine is ended.

In the present embodiment, the line cycle of the thermal head 40 is adjusted or the conveyance speed of the transfer film 46 is adjusted to adjust the length of the image formed in the image forming region Ri, but the adjustment may be performed by combining the two so that the length of the print region Rp (the length of the thermal head 40 in the sub-scanning direction) becomes 86.6[ mm ] even if the image forming region Ri is extended.

In the present embodiment, as shown in fig. 5 a, the flag Ma on the upstream side of the image forming region Ri with respect to the image forming direction is used when the head is sought (when the image formation start position PA is determined), but the flag Mb on the downstream side of the image forming region Ri may be used.

Fig. 5(B) is a diagram schematically showing the image formation start position for the image formation region Ri of the transfer film 46 in the image forming section B1 in the case where the index Mb on the downstream side of the image formation region Ri with respect to the image formation direction is used for the seek. As shown in fig. 5B, the image formation start position PB in the image formation region Ri when the flag Mb is used for head seeking is set to a position 7.7mm from the leading end (in the printing direction) of the flag Mb. In this case, even if the image forming region Ri of the transfer film 46 is extended when the Y color is printed, the position from the marker Mb to the image formation start position Pb does not change, and it is not necessary to adjust the image formation start position when printing of the next color or later. In the present embodiment, since the length from the marker Mb to the image formation start position and the print area Rp does not change, the transfer start position in the transfer portion B2 does not need to be adjusted.

In the present embodiment, the line period of the thermal head 40 or the conveyance speed of the transfer film 46 is changed for each 1 line in order to adjust the length of the image formed in the image forming region Ri, but the adjustment value may be determined so as to be the same for all lines based on the sum of the estimated elongations of the lines (or the average value of the elongation coefficients of the lines).

(second embodiment)

Next, a second embodiment in which the present invention is applied to a printing system including a printing apparatus and a computer will be described. The printing system 100 according to the second embodiment is a system in which the adjustment value determination process (see fig. 8 and S206) described in the first embodiment is performed on the printing apparatus 1 side. In the following embodiments of the second embodiment, the components, functional units, and steps constituting the printing system 100 of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, and only different points will be described below.

The printer driver 153 of the host device 101 includes a conversion processing unit (see also fig. 13 a and S202), a detection processing unit (see also fig. 13 a and S204), and a transmission processing unit (see also fig. 13 a and S208), and does not include the determination processing unit described in the first embodiment. Therefore, the detection processing section stores the attribute information and the record data received from the object generating section 152, the Y, M, C, Bk print data converted by the conversion processing section, and the detected tone value and image formation rate for 1 line in one folder, and the transmission processing section transmits the folder created by the detection processing section to the printing apparatus 1 in accordance with the instruction of the operator.

On the other hand, after receiving the folder from the host device 101 (communication processing unit), the CPU (of the printing apparatus 1) executes the adjustment value determination routine shown in fig. 13(B) before executing the card issuance routine shown in fig. 12. In S254, the CPU executes the same processing as the determination processing section of the printer driver 153 of the higher-level device 101 according to the first embodiment with reference to the print data in the folder stored in the memory 77, and stores the adjustment value of the line period (or the adjustment value of the conveyance speed) and the adjustment value of the image formation start position PA for each 1 line of the print data for each color component in the folder stored in the memory 77. In S254, the ambient temperature detected by the temperature sensor Th is used.

(third embodiment)

Next, a third embodiment in which the present invention is applied to a printing system including a printing apparatus and a computer will be described. The printing system 100 according to the third embodiment is a system in which the tone value and image formation rate detection processing (see fig. 8 and S204) and the adjustment value determination processing (see fig. 8 and S206) described in the first embodiment are performed on the printing apparatus 1 side.

The printer driver 153 of the host apparatus 101 includes a conversion processing unit (see also fig. 14 a and S202) and a transmission processing unit (see also fig. 14 a and S208), and does not include the detection processing unit and the determination processing unit described in the first embodiment. Therefore, the conversion processing section stores the attribute information and the record data received from the target generating section 152 and the converted Y, M, C, Bk print data in one folder, and the transmission processing section transmits the folder created by the conversion processing section to the printing apparatus 1 in accordance with the instruction of the operator.

On the other hand, after receiving the folder from the host device 101 (communication processing unit), the CPU (of the printing apparatus 1) executes the adjustment value determination routine shown in fig. 14(B) before executing the card issuance routine shown in fig. 12. The CPU executes the same processing as the detection processing section of the printer driver 153 of the higher-level device 101 according to the first embodiment with reference to the print data in the folder stored in the memory 77 in S252, executes the same processing as the determination processing section of the printer driver 153 of the higher-level device 101 according to the first embodiment in the next S254, and stores the adjustment value of the line period (or the adjustment value of the conveyance speed) for each 1 line of the print data of each color component and the adjustment value of the image formation start position PA in the folder stored in the memory 77. In S252 (in (c) to (e) of the conversion optionally performed by the conversion processing unit) and S254, the ambient temperature detected by the temperature sensor Th is used.

(modification 1)

In the above embodiment, the adjustment is performed so that the image length of the print area Rp is constant, but the extension of the image forming area Ri may be allowed and the color shift may be prevented when the thermal head 40 forms an image in the print area Rp.

When an extension occurs in the image forming region Ri of the transfer film 46 when an image is formed on the print region Rp with the ink of the first color (e.g., Y), the distance from the marker Ma to the image formation start position PA changes (see also fig. 5 a), and the image formation start position PA is shifted with the ink of the second color (e.g., M), so that a color shift occurs on the image formation start position side. When the extension occurs in the image forming region Ri, the color shift also occurs on the image formation end position side. Therefore, in accordance with the extension of the image forming region Ri, (1) adjustment (correction) of the image formation start position PA and (2) adjustment (correction) of the image length of the print region Rp are required. Note that the adjustment of the image formation start position PA is the same as that in the first embodiment, and therefore, the description thereof is omitted.

Further, when the print area Rp is elongated, the center Cn of the length of the print area Rp in the image forming direction and the center of the card Ca in the longitudinal direction do not coincide with each other. Therefore, adjustment (correction) in the transfer section B2 is also required (3).

(2) Adjustment of image length of print area Rp

As in the first embodiment, the line cycle of the thermal head 40 is changed in accordance with the detected elongation coefficient, and the image length of the print area Rp of the thermal head 40 is adjusted. However, the line period is extended in the present embodiment, compared to the line period shortened in the first embodiment. In the present embodiment, the extension coefficient is determined based on the gradation value printed in the same line of the preceding color, and the line period is adjusted in accordance with the extension coefficient.

Assume that, for example, in the case of printing a predetermined line of M ink, the elongation coefficient is 1.0 as a result of detecting the gradation value of the line when printing Y ink. In this case, as described in the first embodiment, the row is assumed to be elongated 1/2048, that is, about 0.0004883[ mm ]. Therefore, when printing the line of M color, the length of 1 line needs to be adjusted from 0.0422851[ mm ] (86.6/2048[ mm ]) to 0.0427734[ mm ]. Therefore, the determination processing unit determines an adjustment value (adjustment value: + 1.15478%) so that the line cycle becomes 1.0115478 times, and when printing the line, the line cycle is changed from 0.8[ ms/line ] to 0.8092382[ ms/line ]. When the C ink is printed, adjustment is performed to extend the line cycle based on the estimated value of the amount of extension (the sum of the extension coefficients of the respective colors) due to printing using the Y ink and the M ink.

In the case of performing adjustment for extending the line period of the thermal head 40 as matching the print result of the preceding color, adjustment at the time of printing of the Y ink as the first color is not necessary, but adjustment may be performed so as to shorten the line period in accordance with the detected elongation coefficient at the time of printing the Y ink, and adjustment so as to extend the line period at the time of printing the M ink and the C ink with respect to the amount of elongation even in this case. In this case, the elongation coefficients of the M ink and the C ink are reduced according to the adjustment value of the Y ink.

(3) Adjustment of transfer start position

Fig. 6(B) is a diagram schematically showing alignment of the print area Rp and the card Ca when the print area Rp of the transfer film 46 is stretched. In this embodiment, it is assumed that an elongation of 1.5[ mm ] is generated in the entire image formation with the Y, M, C ink in the printing region Rp (the final estimated elongation is 1.5[ mm ] as a result of detecting the tone value and the image formation ratio).

In this case, the amount of 1/2(1.5[ mm ]/[ 2 ] 0.75[ mm ]) for adjusting (correcting) the elongation generated in the printing region Rp in the transfer section B2 is required. That is, the position where the transfer film 46 is conveyed 30[ mm ] +0.75[ mm ] - [ 30.75[ mm ] after the sensor Se3 detects the marker Mb is set as the transfer start position. Thus, even if the print area Rp is elongated, the center Cn of the image length in the image forming direction of the print area Rp can be aligned with the center of the card Ca in the longitudinal direction, and the image transferred to the card Ca can be prevented from appearing to be shifted to one side (especially, conspicuous when a photograph, a LOGO, or the like is placed at the end of the card Ca), or, in some cases, the image on the transfer tip side can be cut at the end side of the card Ca.

Further, in the present embodiment, the melted ink is used as the Bk ink, and in the case of using the melted ink, the degree of absorption in the ink receiving layer of the transfer film 46 is lower (the degree of adhesion to the ink receiving layer is higher) and the elongation of the printing region Rp by the Bk ink is smaller than in the case of using the sublimation ink, so the elongation by the Bk ink is not considered.

The CPU performs the above-described (1) adjustment of the image formation start position PA and (2) adjustment of the print area Rp in the primary transfer processing in S302 and S312 of fig. 12. In addition, in the secondary transfer processing in S306 and S316, the adjustment of the transfer start position (3) described above is performed.

On the other hand, on the higher-order apparatus 101 side, the determination processing unit of the printer driver 153 calculates the elongation of the image length in the print area Rp for each 1 line, and then calculates the total value of the elongations of the print data of all lines. The determination processing unit determines the adjustment value of the line period of the thermal head 40 in accordance with a predetermined relationship between the total value of the elongations of the printing areas Rp of all the lines and the adjustment value of the line period. The determination processing unit determines the above-described (1) adjustment value of the image formation start position PA, (2) adjustment value of the image length of the printing area Rp of the thermal head 40, and (3) adjustment value of the transfer start position.

Then, the determination processing section stores the adjustment values of the above (1) to (3) of the attribute information and the record data received from the target generation section 152, the Y, M, C, Bk print data converted by the conversion processing section, and the Y, M, C print data in one folder.

In addition, when the mark Mb on the downstream side of the image forming region Ri is used for head seeking, the distance from the mark Mb to the image formation start position PB does not change even if elongation occurs in the image forming region Ri of the transfer film 46, and therefore the adjustment of the image formation start position PB in (1) above is not necessary. Therefore, the determination processing unit determines the adjustment values of (2) and (3).

The determination processing section described above shows a mode in which the adjustment value for adjusting the line cycle of the thermal head 40 is determined in accordance with the extension of the print region Rp caused by the printing of the ink of the previous color, but may determine the adjustment value for adjusting the transport speed of the transfer film 46 (adjustment value of the transport speed of the transfer film 46 for each 1 line) without changing the line cycle.

For example, when the elongation coefficient of a predetermined line of Y ink is 1.0[ mm ], the line cycle is maintained at 0.8[ ms/line ] as it is, and the transfer speed of the transfer film 46 is increased by 1.15478% (adjustment value: + 1.15478%) from the reference transfer speed when printing the line of M ink, so that the transfer speed of the transfer film 46 becomes 0.8092382[ ms ], and color shift due to the difference in elongation of the print region Rp between colors can be reduced.

In the present embodiment, the line cycle of the thermal head 40 is adjusted or the transport speed of the transfer film 46 is adjusted to adjust the length of the image formed in the image forming region Ri, but the length of the image may be adjusted by combining the two to adjust the length of the image in accordance with the extension of the print region Rp occurring when printing with the ink of each color, thereby preventing the occurrence of color shift between the respective colors.

In the present embodiment, the line period of the thermal head 40 or the conveyance speed of the transfer film 46 is changed for each 1 line in order to adjust the length of the image formed in the image forming region Ri, but the adjustment value may be determined so as to be the same for all lines based on the sum of the estimated elongation of each line (or the average value of the elongation coefficients of each line).

In addition, although the present embodiment (modification 1) has been described with respect to the differences from the first embodiment, the differences allow the print area Rp to expand and prevent color shifts when the thermal head 40 forms an image on the print area Rp in the second and third embodiments as well.

4. Effects and the like

Next, effects and the like of the printing system 100 according to the above embodiment will be described.

4-1. Effect

In the printing system 100 according to the first to third embodiments, the image length when the thermal head 40 forms an image on the transfer film 46 based on the print data of each color component is adjusted for each 1 line based on the tone value and the image formation rate of the pixel group of the print data corresponding to 1 line in the main scanning direction of the thermal head 40, and the image length of the print area Rp is maintained at a constant value (86.6[ mm ]), so that color shift can be prevented regardless of the elongation generated in the transfer film 46 by the heating of the thermal head 40.

In addition, in the printing system 100 of modification 1, the line period of the thermal head 40 is adjusted (the image length of the print area Rp is adjusted) and the image formation start position PA and the transfer start position are adjusted in all the lines at the time of image formation of the next color (for example, M) and thereafter, based on the extension generated in the transfer film 46 by the heating of the thermal head 40 at the time of image formation of one color (for example, Y), so that color shift can be prevented regardless of the extension generated in the transfer film 46 by the heating of the thermal head 40.

Therefore, in the printing system 100 according to the above embodiment including the modification 1, the heat generation amount of the thermal head 40 can be increased to shorten the image forming time, and the quality of the image formed on the transfer film 46 (card Ca) can be maintained.

4-2. modified examples

In the above embodiment, the indirect printing type printing apparatus 1 is exemplified, but the present invention is not limited to this, and can be applied to a direct printing type printing apparatus that directly prints on the card Ca using the ink ribbon 41. In this case, the structures, positions, and the like of the image forming section, the conveying roller, the sensor, and the like may be appropriately changed. In the above embodiment, the transfer film 46 is exemplified as the medium, but in the case of the direct printing method, for example, the transfer film can be typically applied to a medium having thermal elasticity such as a tube or a film.

In the above embodiment, Bk is exemplified as a color other than Y, M, C, but the present invention is not limited to this, and other colors (for example, gold and silver) may be used. Further, as for the Bk and the print data of other colors, the image length may be adjusted in forming an image according to the gradation value and the image forming rate, as in Y, M, C.

Further, although the above-described embodiment shows an example in which the conversion (generation) of the print data for each color component is performed on the side of the host device 101 based on the image data, the present invention is not limited to this, and the print data for each color component may be generated from the input image data by the printing device 1(CPU) and stored in the memory 77.

In addition, although the above-described embodiment shows an example in which the platen roller 45 is pressure-contacted to the thermal head 40 in the image forming section B1, the thermal head 40 may be pressure-contacted to the platen roller 45. In this case, the platen does not need to be an exemplary roller, and is preferably an example in which the conveyance of the transfer film 46 and the ink ribbon 41 is not affected. Further, although the example in which the heat roller 33 is pressure-contacted to the platen roller 31 in the transfer section B2 is described in the above embodiment, the platen roller 31 may be pressure-contacted to the heat roller 33.

Further, in the above-described embodiment, an example is shown in which an image on one surface side of the card Ca is formed in the image forming region Ri of the transfer film 46 in the image forming section B1 (step 302 of fig. 12), after the image is transferred on one surface side of the card Ca in the transfer section B2 (step 306), the card Ca is conveyed to the side of the rotary member F and rotated by 180 ° in the image forming section B1 in parallel with the image formation on the other surface side of the next image forming region Ri of the transfer film 46 (step 312) (step 314), an image on the other surface side of the card Ca is transferred on the other surface side of the card Ca in the transfer section B2 (step 316), but an image on one surface side of the card Ca may be formed in the image forming region Ri of the transfer film 46 in the image forming section B1, an image on the other surface side may be formed in the next image forming region Ri of the transfer film 46, and in the transfer section B2, after the image is transferred to one surface of the card Ca, the card Ca is conveyed to the side of the turning member F and rotated by 180 °, and the image on the other surface side is transferred to the other surface side of the card Ca.

In the above embodiment, the printing system 100 in which the host apparatus 101 is connected to the printing apparatus 1 is illustrated, but the present invention is not limited thereto. For example, a folder created on the higher-level apparatus 101 side may be delivered to the printing apparatus 1 side via a USB memory, a memory card, or the like. In addition, when the printing apparatus 1 is a member of a local area network, the folder may be transmitted from a computer connected to the local area network. Further, the attribute information and the record data may be input from the operation panel unit 5.

The claims of the present application include "a recording medium having a program recorded thereon, wherein the program causes a computer to function as: a generation unit that generates print data for each color component from the image data; and a detection unit that detects a gradation value of a pixel constituting a pixel group corresponding to 1 line in the main scanning direction of the thermal head of the print data for each color component generated by the generation unit, and an image formation rate indicating a ratio of a number of pixels having a color component to a number of pixels constituting the pixel group corresponding to the 1 line. "in addition to the image length when the thermal head 40 forms an image on the transfer film 46 based on print data for each color component as exemplified in the above embodiment, such a program can be used as a program for forming a high-quality image on the transfer film 46 by adjusting the tension applied to the transfer film 46 in accordance with the gradation value and the image formation ratio, for example. Further, details thereof are disclosed in the specification of Japanese patent application No. 2016-.

Further, the present application claims priority from Japanese patent application No. 2016-.

Claims

1. An image forming apparatus that forms an image on a medium using an ink ribbon having a plurality of colors of ink, the image forming apparatus comprising:

an image forming unit having a thermal head and a medium conveying part for conveying the medium;

a holding unit for holding print data of each color component; and

a control unit that controls the image forming unit,

the control unit adjusts an image length when an image is formed on the medium by the thermal head based on the print data for each color component, based on a gradation value of a pixel constituting a pixel group corresponding to 1 line in the main scanning direction of the thermal head of the print data for each color component stored in the storage unit, and an image formation rate indicating a ratio of a number of pixels having a color component to a number of pixels constituting a pixel group corresponding to the 1 line.

2. The image forming apparatus according to claim 1,

the control unit adjusts an image length when forming an image based on the print data for each color component by changing a line period of the thermal head and/or a conveyance speed of the medium by the medium conveyance section.

3. The image forming apparatus according to claim 1 or 2,

the control unit adjusts elongation in a sub-scanning direction of the thermal head generated in the medium for every 1 line when forming an image based on the print data of each color component, according to the gradation value and the image forming rate.

4. The image forming apparatus according to claim 1 or 2,

the control means adjusts the image length when forming an image based on the print data for each color component so as to be a predetermined constant value.

5. The image forming apparatus according to claim 1 or 2,

the control unit detects the gradation value and the image formation rate from the print data of each color component, and adjusts an image length when an image is formed based on the print data of each color component, based on the detected gradation value and the detected image formation rate.

6. The image forming apparatus according to claim 1 or 2,

the control unit generates print data for each color component from the input image data, and then stores the generated print data for each color component in the storage unit.

7. A recording medium having a program recorded thereon, wherein the program causes a computer to function as:

a generation unit that generates print data for each color component from the image data; and

and a detection unit that detects a gradation value of a pixel constituting a pixel group corresponding to 1 line in the main scanning direction of the thermal head of the print data for each color component generated by the generation unit, and an image formation rate indicating a ratio of a number of pixels having a color component to a number of pixels constituting the pixel group corresponding to the 1 line.

8. The recording medium according to claim 7,

a program for causing the computer to function also as a determination unit that determines an adjustment value of an image length formed based on the print data for each color component when forming an image on a medium by the thermal head, based on the gradation value and the image formation rate detected by the detection unit, is recorded.

9. An image forming system including an image forming apparatus that forms an image on a medium using an ink ribbon having a plurality of colors of ink, and a computer that can communicate with the image forming apparatus, the image forming system comprising:

a generation unit that generates print data for each color component from the image data;

a detection unit that detects a gradation value of a pixel constituting a pixel group corresponding to 1 line in a main scanning direction of the thermal head of the print data for each color component generated by the generation unit, and an image formation rate indicating a ratio of a number of pixels having a color component to a number of pixels constituting the pixel group corresponding to the 1 line; and

and a determining unit configured to determine an adjustment value of an image length formed based on the print data for each color component when the thermal head forms an image on the medium, based on the gradation value and the image formation rate detected by the detecting unit.